# Maximum Difference Of Zeros And Ones In Binary String

easy

1. You are given a string containing only 0's and 1's. 2. You have to find the length of substring which is having maximum difference of number of 0s and number of 1s i.e (Number of 0's - Number of 1's). 3. If there are all 1's present in the given string, then print '-1'.

## Constraints

1 <= length of string <= 10^5

## Format

### Input

A Binary String

### Output

A number

## Example

Sample Input

11000010001

### Sample Output

6